<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <script src="../vue.js"></script>
</head>
<body>
    <div id="app">
        <h2>{{counter}}</h2>
        <!-- <button v-on:click="increment">+</button>
        <button v-on:click="decrement">-</button> -->
        <!-- 语法糖 v-on:click省略为@click -->
        <button @click="increment">+</button>
        <button @click="decrement">-</button>
        <!-- 事件监听 无参数 可以不加() -->
    </div>
    <script>
        const app=new Vue({
            el:'#app',
            data:{
                counter: 0
            },
            methods:{
                increment(){
                    this.counter++;
                },
                decrement(){
                    this.counter--;
                }
            }
        });
    </script>
</body>
</html>